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| Artist view of a binary black hole system. Credit: LIGO/Caltech/MIT/Sonoma State. Credit: Aurore Simonnet |
A group of theoretical physicists has discovered a peculiar structure in space-time that appears to an outside observer to be a black hole, but upon closer study is anything but: they are faults in the fabric of the universe.
The existence of black holes, generated when huge stars collide, is predicted by Einstein’s general theory of relativity. However, the same theory predicts that their centers will be singularities or points of infinite density. We interpret Einstein’s theory as incomplete because we know that infinite densities cannot exist in the cosmos. However, despite over a century of looking for extensions, we have yet to confirm a better theory of gravity.
However, there are candidates, including string theory. String theory states that all particles in the cosmos are minuscule vibrating loops of string. These strings cannot simply vibrate in our three spatial dimensions in order to support the huge diversity of particles and forces that we observe in the universe. Extra spatial dimensions must instead be wrapped up on themselves into manifolds so tiny that they evade daily observation and research.
The exotic structure in spacetime provided a team of researchers with the resources they needed to identify a new class of entity known as a topological soliton. They discovered that these topological solitons are stable flaws in space-time. They don’t need matter or other forces to exist—they’re as natural to the fabric of space-time as ice splits. The findings have been published in the journal Physical Review D.
The researchers investigated these solitons by observing the behavior of light passing near them. Because they are extreme space-time objects, they bend space and time around them, affecting the path of light. These solitons would appear to a distant viewer exactly as we expect black holes to appear. They’d have shadows, light rings, the works. The Event Horizon Telescope images and detected gravitational wave fingerprints would all behave similarly.
It wasn’t until you came close that you realized you weren’t looking at a black hole. One of the most important characteristics of a black hole is its event horizon, which is an artificial surface beyond which you would be unable to escape. Topological solitons lack event horizons since they are not singularities. So, assuming you survive the encounter, you may approach a soliton and hold it in your palm.
Based on our understanding of string theory, which has yet to be demonstrated to be a feasible update to our understanding of physics, these topological solitons are extremely speculative objects. However, these unusual items are important test subjects. If the researchers can identify a significant observable difference between topological solitons and ordinary black holes, they may be able to test string theory itself.